In a rush towards ever-increasing fuel economy, one of the most important contributors is often overlooked. German tyre company Continental is keen for operators to realise the benefits that its products can bring. Tim Deakin explains more.
The tyre market is huge, and buyers have a great amount of choice.
Premium European brands are under fire from budget Asian manufacturers, and in order to combat this threat, they are adopting a ‘complete solution’ approach. Among them is Continental.
Besides its core business of manufacturing new tyres, Continental has two other products which are of interest to the commercial vehicle sector: ContiPressureCheck tyre pressure monitoring, and a high-quality retreading service. The latter sees worn casings cost-effectively returned to almost new condition.
Continental’s priorities, and in which it invests a huge development spend, are achieving the lowest rolling resistance and highest mileage before remanufacturing is required.
In a nutshell that is the simplest route to economical and efficient tyre operation.
Coaches and buses share wheel sizes with LGVs, but the two sectors’ demands are different, says Dr Frank Walloch, Head of Product Development for bus and truck tyres. That’s something Continental must bear in mind.
â€œCoach and bus operators’ primary focus is on safety, while in LGV applications the emphasis is on tyre life,â€ he says.
â€œFeedback tells us that using a truck tyre on a coach or bus is not the best solution. Passenger-carrying vehicles are often driven faster and may corner harder than trucks, although in a small number of niche applications it is the best option.
â€œA higher degree of stability is required in the passenger sector, and noise levels are also more important. But there is a compromise between noise and wet weather performance thanks to tread patterns, and optimising the two is difficult.
â€œTyres used in urban buses must also have thicker sidewalls and a deeper, wider tread base because the wear rate is high. In coach and bus, we also increase the stiffness of the tyre carcass compared with truck to deliver increased stability.â€
In the interests of efficiency and environmental considerations, worn casings that are free from any major structural damage are returned to Continental’s Hanover plant for retreading, a similarly involved process to the design and construction of new tyres. But regardless of the stage of their lives, they must all be looked after.
The pressure is on
Maintaining correct pressures is vital, says Hartwig Khn, Global ContiPressureCheck Manager.
â€œCorrect inflation improves safety, reduces costs and is kinder to the environment,â€ he says, and he echoes Frank’s words that safety is of paramount importance to coach and bus operators. â€œTyre under-inflation is bad in several ways: It increases fuel consumption and damage is more likely, meaning that the casing cannot be reused later in its life.â€
Continental has a barometer for the reduced fuel efficiency of a tyre: Every 1psi below the recommended inflation level means that approximately an additional 4.50 worth of diesel is used per tyre, per year.
That may not sound much, but on a coach with eight tyres, each of which is underinflated by 10psi, it means that around 360 per year is being unnecessarily spent on fuel, or more on high mileage work.
That’s before a reduced life is taken into account; under-inflation leads to excessive head build-up, which is â€œthe enemy of all tyresâ€; Hartwig also points out that braking, handling and wet weather performance can be compromised.
‘Fit and forget’
So how is this dealt with? ContiPressureCheck (CPC) is how, says Continental. CPC is a simple system available in a variety of forms, from one that consists solely of on-vehicle equipment to another that integrates with telematics systems to deliver remote ‘real time’ pressure readings to any web-enabled device.
In between are two options which record pressures when the vehicle returns to base. One requires a person to walk around the vehicle with a hand-held reader; the other uses a remote unit mounted next to fuel pumps, toilet drop areas and so on.
On-vehicle equipment consists of a number of components. Most importantly, each tyre must have a pressure monitor within the casing. They are highly durable and long-lived, says Hartwig. A central control unit (CCU) is also fitted to the chassis, along with an additional receiver in very long PCVs.
The CCU harvests information from the tyre sensors and then feeds it to the end user.
â€œCPC uses the same protocols as telematics systems, so the two can work together. We will also soon announce CPC’s integration into the dashboard displays on a number of OEMs’ vehicles; alternatively, it can be fitted by either the operator or our contractor,â€ says Hartwig.
The system is proving popular. Payback time is around 12 months, and that can be considerably reduced if CPC prevents a breakdown.
â€œEvery operator tells us that it makes sense. We launched CPC two years ago, and we are now reaping the rewards. Business is booming, and demand is rising rapidly.â€
Same ground twice
Besides its safety implications, CPC helps prevent damage to tyres. That means they are more likely to be accepted into the ContiLifeCycle retreading programme.
Retreading worn-out tyres returns them to almost as-new condition, with a useful saving over new.
The process of remanufacturing a tyre is not complicated, but Continental is anxious to show its various quality control systems in a bid to reassure buyers.
â€œWe are trying to offer a used tyre that has all the benefits of a new one,â€ says Constantin Batsch, Vice President Business Region Truck Tyres.
â€œHowever, some operators do not use retreads; some applications require a new tyre, such as those covering very high mileages or under heavy imposed loads.â€ The retreading facility showed that some operators pay little or no attention to tyres at all; at least one awaiting treatment was completely bald.
â€œRetreading is an integral part of a tyre’s life. It’s a different, more cost-effective product, and one which we believe will combat other business models of supplying cheap new tyres,â€ says Constantin.
Blowing hot and cold
Retreading is undertaken either by hot or cold methods, and once the tyre has already been regrooved to extend its first life. A hot retread is more substantial than a cold treatment, which is reflected in the cost saving over a new tyre; it is around 15% less, against 25% respectively.
Retreaded tyres are provided with the same five-year warranty as new casings, and all incoming used tyres receive a thorough check for damage â€“ including a trip through an X-ray machine â€“ before acceptance. Those which do not meet the standards are scrapped.
The ContiPressureCheck and ContiLifeCycle programmes show that tyre manufacturers engage in a similar level of research and development, and unit lifetime management, as builders of much more complex vehicle components. Operators should treat all with equal respect if safety and efficiency are important to them.